#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
	int original_price, discount;
	double discount_price;
	scanf("%d %d", &original_price, &discount);

	discount_price = original_price * discount / 10.0;

	printf("%.2lf", discount_price);
	return 0;
}